David Cameron has admitted for the first time that he will have to change his party's policies because he failed to spot that Britain's economy is 'broken'.

The Tory leader cranked up the pressure on Gordon Brown by offering what amounted to an apology for his part in the financial crisis.

Interviewed last night he explicitly said he was sorry for his mistakes. 'Of course I'm sorry that we have got some things wrong,' Mr Cameron said.

'Actually saying sorry is the easy bit, the difficult bit is for politicians to look back and say right where did I go wrong; it’s that, that needs to take place in order to build this trust with the public so we can get this economy out of recession and into recovery.'

He said the Tories should have spoken out against unsustainable levels of public and private debt but were locked in the 'cosy economic consensus' that gripped all the parties.

In a significant departure, he claimed the downturn had left Britain's economy 'broken' and would have an unavoidable impact on what the party will be able to offer voters at the next election.

His concession paved the way for what is likely to be some significant reordering of policy as the party reviews its tax and spending commitments in the light of the public finance crisis.

In his first speech since the death of his son Ivan three weks ago, Mr Cameron admitted the Tories had based their plans on generous assumptions of economic growth that are now in tatters.

The Tory leader came the closest he has yet to admitting that his spending pledges, which range from substantial cuts in inheritance tax to reductions in corporation tax and giveaways for families, may have to be reviewed.

Mr Cameron's candour will reignite the debate over whether or not the Prime Minister should apologise for his role in the downturn.

Mr Brown has bitterly resisted calls from some of his closest allies who want him to say sorry as a way of neutralising growing voter anger at the scale of the downturn.

In a speech to the Birmingham Chambers of Commerce, Mr Cameron said: 'I know the scale and nature of this economic crisis means change in our policies and our hopes for what we can achieve in government.'

He said he planned to start answering some of the questions critics have aimed at the Tories about their plans for getting Britain out of recession and restoring health to crippled public coffers.

He accused Mr Brown of failing to understand the depth of the crisis, and of believing it could be cured with 'a few sticking plasters to an otherwise healthy body'.

Echoing a theme used by Shadow Chancellor George Osborne last week, he said the banking crisis was a reflection of a debt crisis affecting households and the Government.

He added: 'But if I’m honest, I have to admit that we – the Conservative Party – didn’t see this as early as we could have.'

He defended his decision to make repairing what he calls Britain's 'broken society' a priority. The Tories had begun warning in 2006 about rising levels of personal debt, and had highlighted rising Government debt at the last election, he said.

'But do I believe we did enough to warn about the rising levels of corporate debt, banking debt and borrowing from abroad? No,' he added.

Busy: Unemployment has soared because of the recession

In a significant departure that paves the way for a policy re-write, Mr Cameron added: 'There are other areas of economic policy where I look back now and think we would have done it differently if we had the time again.

'For example, while we warned that it was wrong and complacent to claim that boom and bust had been abolished… we based our plans on the hope that economic growth would continue.'

He added: 'It is only by being honest about the past that we can get things right for the future. So we need to recognise that our economy, as well as our society, is broken - and we should have said so sooner.

'But if we’re honest, we must also recognise that some of our economic difficulties today relate not only to what has happened in the last ten years, but also to certain fundamental weaknesses that have been there for decades.

'In recent years these fundamental British economic weaknesses have actually been getting worse rather than better, but they have been masked by easy money and economic growth.

'It's only when the tide of debt-fuelled growth recedes that the rocks underneath are revealed. Well the tide is out now, and the rocks all too visible. We as a country can’t get away with it any more.'